The objectives of this work are to develop analytic understanding of the cellular aspects of immune memory and to devise experimental conditions for the future development of effective cancer immunotherapy. We will study the generation of memory in vitro for both humoral and cell mediated immune responses. Memory will be analyzed separately for the different functional classes of immunocompetent cells. We shall seek through empirical means to develop conditions for the selective generation of cell mediated and/or of humoral immune memory. Bibliographic references: Chan, E. L. and Mishell, R. I. (1975). Suppression of the generation of cell mediated cytotoxicity by spleen cells previously sensitized in vitro: an example of a persisting immunosuppressive function of T cells. Federation Proceedings 34, 1037 (Abstract).